Self-driving cars could reduce the huge amount of space devoted to parking in the U.S. while making the roads safer, the head of Google's self-driving car program says in prepared remarks for a Senate Commerce Committee hearing Tuesday.

Government won't need to spend as much on driving infrastructure -- roads, garages and public transportation -- as the self-driving car revolution takes hold, Chris Urmson says in the testimony, obtained by Bloomberg News. The impact could be huge, especially given that all the parking in America adds up to a space as large as the state of Connecticut.

“Congress has a huge opportunity to further this field by enabling the U.S. Department of Transportation to pave the way for the deployment of this innovative safety technology,” Bloomberg News quotes Urmson as saying in the prepared testimony.

Google has been a leader in self-driving cars. It operates a fleet of them from its headquarters in California's Silicon Valley. Many envision a future in which fleets of self-driving cars prowl the streets picking up and delivering passengers with the kind of efficiency that means many people would no longer need to own their own vehicles.

But some experts aren't ready to proceed so quickly.

Mary Cummings of Duke University, who is also expected to testify, says in her remarks that more testing is needed.

She says she is among those who "enthusiastically support the research, development, and testing of self-­driving cars" because "human limitations and the propensity for distraction are real threats on the road,"

Cummings adds, however, that, "I am decidedly less optimistic about what I perceive to be a rush to field systems that are absolutely not ready for widespread deployment, and certainly not ready for humans to be completely taken out of the driver’s seat.”